Hermetic motor-compressor

ABSTRACT

A hermetic motor-compressor assembly includes a direct-coupled motor and compressor spring mounted as a unit in a sealed container. The compressor is of the four cylinder Scotch yoke type, with two pairs of opposed coaxial cylinders at right angles on horizontal axes, the pistons of the opposed aligned cylinders being paired by means of a rigid combined yoke and dual connecting rod assembly. The yokes are actuated by rectangular slide blocks fitted on a common crank throw. The yokes and blocks are keyed against displacement with respect to the axes of the cylinders. Suction gas is separated from entrained liquid and guided downwardly in paths close to the motor and through connected passages in the compressor body and out at the bottom.

United States Patent 1191' Gannaway 1 Apr. 30, 1974 [5 HERMETICMOTOR-COMPRESSOR 3,167,293. 1/1965 Stenger 417/902 1 2-122-322 2/122;11;:1i:;;;;; 211/21: 73 Assigneez Copeland Corporation Sidney Ohio3,577,891 5/1971 Katsuta-shi 417/269 [22] Filed: July 1973 PrimaryExaminerC. J. Husar [2]] Appl. N 381,627 Attorney, Agent, or Firm -JohnC. L. Cowen Related US. Application Data v [63] Continuation of Ser. NO.259,694, June 5, 1972, [57] ABSTRACT abandoned Continuation-impart ofSen N04 A hermetic motor-compressor assembly includes a di- 1970-rect-coupled motor and compressor spring mounted as a unit in a sealedcontainer. The compressor is of the [52] 1.1.5. C1 417/415, 417/312,417/534, four Cylinder Scotch yoke type, with two pairs of 417/902 posedcoaxial cylinders at right angles on horizontal [51] lift. C1. F041)17/00 axes, the pistons of the Opposed aligned cylinders [58] Field OfSearch 417/312, 313, 360, 415, being paired by means of a rigid combinedyoke and 417/534 902 dual connecting rod assembly. The yokes areactuated by rectangular slide blocks fitted on a common crank [56]References C'ted throw. The yokes and blocks are keyed against dis-UNITED STATES PATENTS placement with respect to the axes of thecylinders. 2,893,626 7/1959 Weibel 417/312 Suction g is separated from nr ined liquid and 2,823,850 2/1958 Hintz 415/415 guided downwardly inpaths close to the motor and 2,965,289 2/1960 Weibe1..,.. 417/902through connected passages in the compressor body 3,008,629 11/1961Gertis .1 417/902 and out at the bottom, 3,031,861 5/1962 McCormack417/902 3,101,891 8/1963 Frank 417/312 5 Claims, 13 Drawing Figures 7/74 7 7a /2 II II ATENTEDAPR 30 1914 SHEET 1 UF 5 MTENTEDAPREIO m43'807'907 SHEET 2 0F 5 PATENTEDAPRBO m4 7 SHEET 3 [IF 5 PAIENTEDmso 1914HERMETIC MOTOR-COMPRESSOR This is a continuation, division, ofapplication Ser. No. 259,694, filed June 5, 1972 now abandoned.

BACKGROUND OF THE INVENTION This application is a continuation-in-partof my prior application Ser. No. 6,158, filed Jan. 27, 1972, now U.S.Pat. No. 3,695,786.

The objects of the present invention can be summarized as to provide animproved hermetically sealed motor-compressor assembly designed forrefrigeration service and which incorporates, to a degree which is highin proportion to the cost of the unit, the following characteristics, towit: low noise, effective separation of liquid entrained with returninggas, efficient cooling of the motor, compactness, and rugged, reliableconstruction, and to provide improved lubrication with reducedlikelihood of drawing oil into the .valves of compressors designed to beemployed in refrigeration service.

Other objects and advantages will become apparent upon consideration ofthe present disclosure in its entirety.

BRIEF DESCRIPTION OF THE FIGURES OF DRAWING FIG. 1 is a verticaldiametric sectional elevational view of a refrigeration motor-compressorof the hermetic type, incorporating a preferred form ofthe invention;

FIG. 2 is a cross section taken substantially on the line ll-II of FIG.I, and looking in the direction of the arrows;

FIG. 3 is a fragmentary sectional view of the compressor body with otherparts omitted, takensubstantially as indicated by the line and arrowsIII.III on FIG. 2;

FIG. 4 is a fragmentary elevational view of the body, with other partsremoved, taken substantially as indicated by the line and arrows lV-IVon FIG. 1;

FIG. 5 is a cross section taken substantially on the line V-V of FIG. 1and looking in the direction 'of the arrows;

FIG. 6 is a sectional detail taken as indicated by the line VI-VIof'FIG. 1, and looking in the direction of the arrows, but with thecrank throw in a different position;

FIG. 7 is a fragmentary'diametric sectional view on a larger scaleof thevalve mechanism and associated parts;

FIG. 8 is a bottom plan view of the discharge valve retainer;

FIG. 9 is a bottom plan view of the compressor body;

FIG. 10 is a plan view of the discharge baffle plate;

FIG. 11 is,a plan view of the discharge cover;

welded casing of a refrigeration motor-compressor containing in itsupper portion, on a vertical axis, an induction-type electric motorgenerally designated 12, the armature shaft 14 of which projectsdownwardly from the electric motor and is formed with an integralcrankshaft portion 15 having a single throw 16 which is of sufficientaxial length to accommodate two Scotch yokes 20, 21 mounted side-by-sidethereon in perpendicular horizontal planes.

The compressor body 22 is formed as a rigid casting boredtransversely toprovide two pairs of coaxial cylinders, one pair, comprising cylinders24, 25, being aligned with the upper yoke 20 and having pistons 26, 27rigidly connected to the yoke 20 by colinear connecting rod portions 28,29, while the cylinders 30, 31 of the other pair, upon an axisperpendicular to the axis of cylinders 24, 25, have their pistons 32, 33similarly with radial ears 38 which carry horizontally arranged helicalcompression springs 40 trapped between and coacting with spaced inwardlyprojecting arms 43 of U-brackets 42 secured to the interior of thecasing 10 to absorb torsional forces. The ears 38 are internallythreaded conformably to, and to receive, the springs 40, but midconvolutions of each spring are distorted, as by having a differentlead, so that when fully threaded into the centered position the springis frictionally held. A rubber-like cup 44 is fitted over each end ofeach spring to further reduce sound conduction to the case.

A web section 45 of the' body 22 positioned between the motor andcompressor sections carries a central bearing neck 46 for the shaft. Abottom discharge cover 50 secured to the body by machine screws as 52incorporates a bottom bearing 54 for the shaft and also includesdischarge chamber areas 55 communicating with coacting discharge cavityportions as 56 in the body, such portions being proportioned to provideFIG. I2 is a vertical longitudinal sectional view of a DETAILEDDESCRIPTION OF PREFERRED FORMS OF THE INVENTION Reference character 10designates generally the sleeve 66 has an inwardly projecting flange 67at its upper end bounding a relatively large central opening 68 leadinginto the interior of the sleeve 66 from the upper interior of thecasing. A dished shield and spring locating member 70 overlies theopening 68 and is secured as by tack welds, designated 72, to the flange67, the principal area of the overlying flange portion 7 of the member70 being spaced above the, flange 67, thereby providing an annularhorizontal entrance opening for the suction gas between the flanges 67,74. The flange 67 is defined by a depressed top portion of the shieldingsleeve 66 so that the entrance 75 is surrounded by an annular upwardlybulged bead 76. Oil

and/or liquid refrigerant which may be entrained with the returningsuction gas tends to fall to the oil. sump area at the bottom of thecasing, but if any droplets are carried upwardly and radially inwardlytoward the entrance 75, their inertia will be such that they are guidedaway from the entrance by the bulge 76 sothat as a practical matter onlydry gas finds its way intothe space within the sleeve 66.

The sleeve 66 is somewhat outspaced from the stator 36, so that thespace within the sleeve around the motor communicates with channels 77formed in the inner wall of the supporting portion 34 of the body andextending downwardly from its top to the space 78 below the statorinside the support portion 34. The support portion 34 and sleeve 66 areimpervious, and the downflowing gas travels not only through the spacearound the stator, but also through the space between the stator and thearmature, and through additional passages as 80 in the armature. Theincreased cross sectional area for gas flow provided by the paths aroundthe motor reduces the pressure drop in the motor section yet guides thereturning gas in close wiping engagement with the motor, to achievemaximum cooling of the motor from the residual heat absorbing capacityof the gas. The reduced pressure drop offsets the tendency of thecompressor to pull oil out through any bearing clearance and into itselfwhere objectionable noise and/or valve damage might occur.

A perforated baffle plate 79 in support portion 34 and spaced above web45 creates a muffling chamber 81. The holes 84 in plate 79 areproportioned to tune the muffling chamber 81 for maximum sound deadeningconsistent with efficient operation. Vertical passages 82 in the body 22have their tops open in the upper surface of web 45 in chamber 81, andconduct the gas via passages 82 and communicating horizontal passages 83to the suction spaces 87 in the cylinder heads. Ring-type suctionvalves85 admit gas to the cylinders on the suction strokes, and centrallypositioned discharge valves 88 admit the compressed gas to headcompression chambers 90. The annular reed type discharge valves 88 areloosely fitted (e.g.: 0.0060.01O

' inch clearance) on the hub portion 86 of the discharge valve retainer89 which is of T-section and which is secured to the outer face ofthevalve plate by an axial rivet 91. Thus the movement of compressed gasinto the head is unobstructed. The valve is biased against its seat onthe plate by a spring 93 between the valve and the head of the retainer.Due to the fact that the valve is formed of thin material, and due tothe aforementioned clearance between the retainer hub and the hole inthe valve, it has been found feasible to dispense with the moreconventional cage-type retainer without loss of reliability of valveoperation. Compression chambers 90 communicate via passages 92 with thedischarge muffling chamber 56, from which the gas is conducted throughholes 57 in discharge baffle plate 58 into mufflering chamber portions55 in discharge cover 50 and thence to the connecting discharge tube 95leading to the discharge fitting 96 on the exterior of the casing.Additional sound deadening is caused by the fact that the oil in thesump constituted by the bottom of casing engages the exterior of theparts which define the muffling chambers 55, 56.

Each of the yokes 20, 21 is actuated by a rectangular slide block 100,101. The slide blocks are journaled on the throw 16, and are slightlyspaced from each other therealong, and from the cheeks 1'7, 19 of thecrankshaft.

In the preferred construction shown, each connecting rod portion isintegral with its piston, and an axial hole 102 is drilled through thepiston and connecting rod to receive a screw 104 which secures thepiston and connecting rod to the yoke, as shown in FIG. 1. The slideblock is prevented by the crank throw from rocking around the cylinderaxis, and a keying device comprising a U-shaped sheet metal member 105is secured to the yoke and is provided with flat side arm portions 106,107 overlying the yoke and the block and preventing any relativedisplacement of the yoke and block. In the construction shown, theU-shaped keying member 105 has its bight portion clamped between theyoke and the connecting rod, where it is held when the screw 104 istightened, as shown in FIG. 1. Two of the keying devices 105 areprovided for each yoke, one clamped to each connecting rod, so thatmovement of the parts in any plane in a manner which could result innoisemaking contact is effectively prevented. The side portions 106, 107of each keying device extend the effec tive length of slide blocktravel.

Oil is conducted to the bearing areas through an offset vertical riserpassage 110 in the crankshaft. Oil from the sump area 11 is fed to theriser through a central bottom hole 111 in a disc 112 which closes thebottom of a radial pumping slot 114 formed in the lower end of the shaftand leading to the riser hole. Lateral branch passages 115, 1 16, 117conduct oil from the riser to the bearings. Above the topmost lubricantfeeding passage 117 an upwardly inclined blind continuation passage 118extends back through and beyond the axis of the shaft to a position nearthe surface, where it communicates with an upward riser extensionpassage 119. which is open at the upper end of the shaft. It should benoted that the opening 119' at the upper end of the extension portion119 of this passage system is above any position where a materialpressure drop has occurred due to gas flow through the motor, and isclose to and in the path of the main flow of suction gas enteringthrough inlet 68. Thus a desirable (and substantially balanced) pressureis maintained at the upper and lower ends of the lubrication system, andthe tendency to draw oil from the lubricant passage system is furtherreduced by the ram effect exerted onthe upper end of the riser by thevelocity head of the inflowing suction gas. Gas which has been dissolvedin the oil nevertheless escapes through the opening 119' but the oil iseffectively retained.

FIGS. 12 and 13 illustrate a belt-driven yoke-type compressor, theconstruction of which is fully disclosed in my prior application Ser.No. 6,158, filed Jan. 27, 1970. The lubrication system includes two oilsumps, comprising a high-pressure sump contained in the discharge cover126 and from which oil for lubrication of the working parts is forced bythe discharge pressure through a capillary tube 128 into a lowerpressure sump 130 formed partly in the compressor body 132 and partly inthe bottom head 133. The pressure in the low pressure sump exceedssomewhat the pressure existing in the crankcase and at the locations ofthe working parts, so that the pressure in the low-pressure sump forcesthe oil through a passage system 134, 135, 136, the passages 136comprising branches from the crankshaft passage 135 to the bearingsurfaces.

From the top of the low-pressure sump 130 a venting passage 140 extendsupwardly through the body to the top where it communicates withcontinuation passages 141, 142, 143, the latter of which has a mouth 144which opens into inlet chamber 145 at a position opposite the suctiongas inlet to such chamber. The suction gas is delivered to thecompressor through a fitting 146 which directs the gas, as indicated bythe arrow in H6. 12, in a direction toward the mouth 144, so that thevelocity head of the suction gas tends somewhat to augment the pressureat the mouth 144 and oppose an undue reduction, through the vent, of thepressure in the sump 130. The suction gas continues downwardly viapassages generally designated 148 to the crankcase area 150 and due tothe further pressure drop occurring during its passage to such area itwill be recognized that a pressure differential is maintained such thatthe lubricant is forced to the bearing areas in the manner previouslydescribed. The slightly elevated pressure in the sump 130 is maintainedor augmented by the above-described action through the vent system.

This Detailed Description of Preferred Forms of the Invention, and theaccompanying drawings, have been furnished in compliance with thestatutory requirement to set forth the best mode contemplated by theinventor of carrying out the invention. The prior portions consisting ofthe Abstract of the Disclosure and the Background of the invention arefurnished without prejudice to comply with administrative requirementsof the Patent Office.

What is claimed is:

l. A refrigeration motor-compressor of the type having motor andcompressor components enclosed in a sealed container, which containerhas an inlet through which suction gas is delivered to the interior ofthe container at a position outside both components, the compressorcomponent having an inlet for receiving gas from the interior of thecontainer, a gas-conducting guide surrounding at least a part of themotor component for guiding suction gas over the motor component to theinlet of the compressor component, the guide having a gas inlet whichopens thereinto from the container at a position remote from saidcompressor component inlet, said guide having an outlet coupled to theinlet of the compressor component in substantially gastight relation,the motor and compressor components of said motor-compressor beingarranged substantially coaxially and coupled to a common shaft, thecompressor component having a body containing said inlet of thecompressor on a side toward the motor component, the guide including apart formed as an integral upward extension of said body and extendingaway from the compressor component around the motor, characterized by aplurality of generally annular axially spaced partitioning portionslocated between the motor and compressor components and defining anannular suction muffling chamber having inlet portions opening thereintofrom said guide and outlet portions leading to the inlet of thecompressor component, one of said partitions being integral with thebody and the other partition comprising an orificed plate fitted in andoccupying the full cross section of the interior of said extension.

2. A motor-compressor as defined in claim 1 wherein the lower partitionis integral with the body and the upper partition is defined by saidorificed plate.

3. In a refrigeration motor-compressor including a casing having an oilsump space in a bottom area thereof, a compressor mounted near thebottom therein and having a shaft extending upwardly therefrom withinthe casing, a motor in the casing above the compressor for driving theshaft, and means for conducting compressed fluid from the compressor andfor supporting the compressor and motor as a unit within the casingcomprising a generally annular discharge cover secured to the bottom ofthe compressor, said cover having annularly arranged muffling chamberportions therein, bearing means for said shaft carried by said coverspaced radially inwardly from said chamber portions, an annular upwardlyreentrant spring pocket in said cover between said muffling chamberportions and bearing means, oil pumping, pickup and feeding meanscarried by the shaft and extending downwardly through the bearingmeansand into the oil sump space, and a compression coil springextending upwardly into said pocket from the bottom of the casing andreacting against said cover to support the motor-compressor.

4. A refrigeration motor-compressor assembly of the type having a motorcomponent and a compressor component, said components being enclosed ina sealed container, which container has an inlet through which suctiongas is delivered to the interior of the container at a position outsideboth components, the compressor component having an inlet for receivinggas from the interior of the container, a gas-conducting guidesurrounding at least a part of the motor component for guiding suctiongas over the motor component to the inlet of the compressor component,the guide having a gas inlet which opens thereinto from the container ata position remote from said compressorcomponent inlet, said guide havingan outlet coupled to the inlet of the compressor component insubstantially gastight relation, the two components being directcoupledby coaxial vertical shaft portions, the inlet to the guide beinggenerally coaxial with the shaft portions at the motor end,characterized by diverting means carried by the guide and surroundingthe inletthereto for deflecting heavier constituents away from saidinlet, said guide including an inturned annular flange at its upper enddefining a central inlet orifice, the diverting means includinganupwardly extending rim portion surrounding and outspaced from saidorifice, and a shield overlying said orifice and extending outwardlytoward but spaced from the rim portion and spaced above the orificedportion of the flange.

5. A motor-compressor as defined in claim 4 wherein said shield andguide are rigidly secured to said components, and spring locating meanson said shield and extending into but spaced from the periphery of saidorificc.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent 3, 807,907Dated April 3Q, 1974 Invent0r(X) Edwin L. Gannaway It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 1, line 8, "1972" should be 1970 Column 2, line 61, "7" should be74 Column 3, line 59, "connecting" should be connected Signed and sealedthis 27th day of Augns t 1974.-

(S EAL) Attest:

MCCOY Mo GIBSON, JR. C. MARSHALL DANN Attesting Officer Commissioner of"Patents FOP-M [JO-1050 (M9) USCOMM-DC suave-ps9 UTS. GOVERNMENT PRINTINGOFFICE: 15, 0-36533

1. A refrigeration motor-compressor of the type having motor andcompressor components enclosed in a sealed container, which containerhas an inlet through which suction gas is delivered to the interior ofthe container at a position outside both components, the compressorcomponent having an inlet for receiving gas from the interior of thecontainer, a gasconducting guide surrounding at least a part of themotor component for guiding suction gas over the motor component to theinlet of the compressor component, the guide having a gas inlet whichopens thereinto from the container at a position remote from saidcompressor component inlet, said guide having an outlet coupled to theinlet of the compressor component in substantially gas-tight relation,the motor and compressor components of said motor-compressor beingarranged substantially coaxially and coupled to a common shaft, thecompressor component having a body containing said inlet of thecompressor on a side toward the motor component, the guide including apart formed as an integral upward extension of said body and extendingaway from the compressor component around the motor, characterized by aplurality of generally annular axially spaced partitioning portionslocated between the motor and compressor components and defining anannular suction muffling chamber having inlet portions opening thereintofrom said guide and outlet portions leading to the inlet of thecompressor component, one of said partitions being integral with thebody and the other partition comprising an orificed plate fitted in andoccupying the full cross section of the interior of said extension.
 2. Amotor-compressor as defined in claim 1 wherein the lower partition isintegral with the body and the upper partition is defined by saidorificed plate.
 3. In a refrigeration motor-compressor including acasing having an oil sump space in a bottom area thereof, a compressormounted near the bottom therein and having a shaft extending upwardlytherefrom within the casing, a motor in the casing above the compressorfor driving the shaft, and means for conducting compressed fluid fromthe compressor and for supporting the compressor and motor as a unitwithin the casing comprising a generally annular discharge cover securedto the bottom of the compressor, said cover having annularly arrangedmuffling chamber portions therein, bearing means for said shaft carriedby said cover spaced radially inwardly from said chamber portions, anannular upwardly reentrant spring pocket in said cover between saidmuffling chamber portions and bearing means, oil pumping, pickup andfeeding means carried by the shaft and extending downwardly through thebearing means and into the oil sump space, and a compression coil springextending upwardly into said pocket from the bottom of the casing andreacting against said cover to support the motor-compressor.
 4. Arefrigeration motor-compressor assembly of the type having a motorcomponent and a compressor component, said components being enclosed ina sealed container, which container has an inlet through which suctiongas is delivered to the interior of the container at a position outsideboth components, the compressor component having an inlet for receivinggas from the interior of the container, a gas-conducting guidesurrounding at least a part of the motor component for guiding suctiongas over the motor component to the inlet of the compressor component,the guide having a gas inlet which opens thereinto from the container ata position remote from said compressor component inlet, said guidehaving an outlet coupled to the inlet of the cOmpressor component insubstantially gas-tight relation, the two components beingdirect-coupled by coaxial vertical shaft portions, the inlet to theguide being generally coaxial with the shaft portions at the motor end,characterized by diverting means carried by the guide and surroundingthe inlet thereto for deflecting heavier constituents away from saidinlet, said guide including an inturned annular flange at its upper enddefining a central inlet orifice, the diverting means including anupwardly extending rim portion surrounding and outspaced from saidorifice, and a shield overlying said orifice and extending outwardlytoward but spaced from the rim portion and spaced above the orificedportion of the flange.
 5. A motor-compressor as defined in claim 4wherein said shield and guide are rigidly secured to said components,and spring locating means on said shield and extending into but spacedfrom the periphery of said orifice.